The invention relates to a sheet-metal flat seal layer and a single-layer or multiple-layer flat seal which has a sheet-metal layer of this type, a blank of a sheet-metal layer of this type and a method for the production of a flat seal layer of this type.
Metallic flat seals often consist of a single-piece sheet-metal layer or a plurality of substantially congruent sheet-metal layers or one sheet-metal layer functioning as a carrier layer on which sheet-metal coatings are arranged on one or both sides. Typically, the one sheet-metal layer or at least one of the sheet-metal layers extends over the whole so-called sealing gap to be sealed by the flat seal between two components connected to one another.
In particular, the invention relates to metallic flat seals of the aforementioned type with one or more medium through openings for gases and/or liquids, wherein said flat seals have medium-sealing devices associated with the medium through openings—one such medium-sealing device can have, for example, the form of a bead which encloses a medium through opening and which was impressed into a sheet-metal layer of a flat seal of this type.
Particularly for large metallic flat seals which are subject to relatively high and high operating temperatures, such as elongate exhaust manifold seals, intake manifold seals and cylinder head seals for multiple-cylinder internal combustion engines, the material costs are usually a decisive factor since expensive spring steels and/or steels able to withstand high temperatures must be used for these flat seals and, in this regard, it should be noted that the material costs are high even if steels initially not having resilient properties are processed and are then given resilient properties by means of a heat treatment.